46 LECTURES ON IMMUNITY 



acid at ordinary room temperature. After a certain 

 time he injected this mixture subcutaneously into a guinea- 

 pig. The animal was not killed by the poison; but if 

 before the injection the hydrochloric acid was neutralised 

 by sodium hydrate, the animal was killed. Ritchie inferred 

 that the tetanolysin had been destroyed by the hydro- 

 chloric acid, and was restored by the addition of the base. 

 The simple explanation is the following: The quantity of 

 acid added was not sufficient to cause a rapid destruction 

 of the tetanolysin at the low temperature of the room. But 

 after the subcutaneous injection the temperature of the 

 mixture rose rapidly to about 37 C, and therefore corre- 

 spondingly the destruction of the tetanolysin went on with 

 great speed according to the figures given above about 

 200,000 times more rapidly than at 20 C. before it had 

 time to diffuse into the body of the animal. Therefore 

 the poison was nearly instantaneously destroyed, and had 

 no sensible action on the animal. But if before the injec- 

 tion of the mixture the acid was neutralised (at room 

 temperature) by the addition of an equivalent quantity of 

 sodium hydrate, then the poison was not destroyed after 

 its injection, and could therefore exert its fatal influence. 

 It is not at all necessary to assume such a wonderful pro- 

 cess as a restoration of the destroyed toxin-molecules by 

 the addition of the base. 



For antitoxins, very few investigations have been car- 

 ried through regarding their destruction in time. Madsen 

 found for antiricin (serum of an injected goat) that its 

 strength fell at room temperature to 40 per cent in forty- 

 seven days and to 19.6 per cent in eighty-nine days, which 

 corresponds rather closely to a monomolecular process ; 



